Data recording/reproducing apparatus, file management method, file system information generation method, file management method, file system information generation apparatus, file system information analysis apparatus and medium.
The present invention relates to a data recording/reproducing apparatus for recording/reproducing digital stream data. Furthermore, it relates to a data recording/reproducing apparatus for recording/reproducing digital video and audio stream data as files.
Various digital interfaces and peripheral apparatuses connected thereto have been developed at present. In addition, it has been increasing to control the peripheral apparatuses by using personal computers, thereby to record/reproduce video and audio signals.
In accordance with the progress of such technologies, problems described below at 1) to 6) have been caused. Those conventional technologies and problems related thereto will be described below.
1) A control apparatus and a conventional recording/reproducing apparatus connected thereto will be described. FIG. 43 is a block diagram showing the configuration of the conventional recording/reproducing apparatus. In FIG. 43, the numeral 401 represents a control apparatus, the numeral 402 represents a transmission line, the numeral 403 represents a recording/reproducing unit, the numeral 404 represents an operation panel, the numeral 415 represents an operation signal, the numeral 411 represents data, the numeral 413 represents a response, the numeral 412 represents a command, the numeral 408 represents a recording/reproducing apparatus, the numeral 406 represents an IEEE1394 Interface (hereinafter referred to as an I/F), the numeral 405 represents a processor, and the numeral 414 represents a control signal.
The operation of the recording/reproducing apparatus configured as described above will be described.
The control apparatus 401 is connected to the recording/reproducing apparatus 408 by the transmission line 402. In the transmission and reception of the data 411 and the command 412 between the control apparatus 401 and the recording/reproducing apparatus 408, the data 411 to be recorded is transmitted from the control apparatus 401 to the recording/reproducing unit 403 via the I/F 406, and the command 412 is transmitted to the processor 405 during transmission; the reproduced data 411 is transmitted from the recording/reproducing unit 403 to the control apparatus 401 via the I/F 406, and the response 413 to a specific command 412 required to be responded to the control apparatus 401 is transmitted in the same way from the processor 405 to the control apparatus 401 via the I/F 406 during reception. Furthermore, the operation panel 404 generates the operation signal 415 for instructing the operation of the recording/reproducing unit 403; the processor 405 outputs the control signal 414 for controlling the recording/reproducing unit 403 to the recording/reproducing unit 403; and the recording/reproducing unit 403 records the data 411 on a recording medium or reproduces the data 411 from the recording medium on the basis of the control signal 414.
In the above-mentioned conventional configuration, when the processor 405 receives the operation signal 415 generated by the operation panel 404 during the transmission/reception of the data 411 and the command 412 between the control apparatus 401 and the recording/reproducing apparatus 408, the processor 405 controls the recording/reproducing unit 403 on the basis of the operation signal 415, whereby trouble occurs during the transmission and reception, causing a problem of making the recording/reproducing apparatus 408 malfunction.
2) Furthermore, the contents of data recorded on a recording medium are generally grasped only by an individual who carried out recording; in addition, efforts to attach a seal to the recording medium, to put a list in a cassette case and keep them together, and the like are required. Besides, in actual reproduction, in the case when the recording medium is a tape, search for portions where data is recorded is required while checking the contents by fast forward operation, thereby causing a problem of improper operability.
3) Furthermore, when MS-DOS is taken as an example for explanation, such a data recording apparatus as a hard disk (hereinafter referred to as an HDD) of a conventional personal computer (hereinafter referred to as a PC) is configured to have a boot sector having physical characteristics of the disk and a routine for booting (starting) the computer, a file allocation table indicating locations where individual files are recorded on the disk in cluster units, a root directory wherein the entries of files and subdirectories are recorded, and a file area wherein subdirectories and data are recorded, thereby being capable of recording files.
A file entry used as information regarding a file comprises information of 32 bytes including a file name (eight bytes), an extension (three bytes), a file attribute (1 byte), a creation date and time or the last renewal date and time (four bytes), a recording position (two bytes) indicated by the first cluster number, a file size (four bytes), etc. Among these, the file attribute is information for indicating what kind of characteristics the file has, and the individual bits thereof are supposed to indicate file/read-only/hidden file/system file/volume label/subdirectory/archive file, etc. Furthermore, the extension indicates what kind of computer software the file is compatible with.
In actual operation, the PC transmits commands to the HDD, and a data reading instruction and data the number of bytes of which has been designated are transmitted, whereby file data is read; in a similar way, a data writing instruction and data the number of bytes of which has been designated are received, whereby file data can be written. In reading/writing files, instructions are not issued in file units, but a proper byte length is designated and data is transferred; furthermore, since instruction issuing timing is not controlled, the transfer rate of file data is not constant. The rate depends on the inherent transfer rate of the HDD and the processing speed of the PC; furthermore, when the PC is carrying out another process, the processing speed of the PC may be affected thereby.
This kind of system cannot treat data required to have a real-time characteristic, in particular, video data, audio data, etc; however, since data treated by computers at present includes a lot of data required to have a real-time characteristic, such as video and audio data, the above-mentioned system is improper.
Furthermore, in the case when data is transferred to a sequentially recording/reproducing medium such as a tape instead of the HDD, repositioning, that is, a method wherein operation, interruption, slight rewinding and operation once again are repeated, is carried out to adjust the difference between the transfer rate and recording rate; however, since this operation takes time, and the actual transfer rate becomes lower. To solve this problem, a method of preventing the repositioning is available wherein the difference between the transfer rate and the recording rate is recorded as a dummy; however, if recording is carried out in accordance with this method, the amount of data treated in byte units is changed; when data is copied or moved between different recording media, checking empty areas and the like cannot be accomplished, even if attempted.
4) Furthermore, a home-use digital VCR xe2x80x9cDVxe2x80x9d (Digital Video) using a magnetic tape is available as a medium for storing multimedia information including video and audio data at present. It is now under consideration to connect this DV to a PC and to use it as a recording medium for the PC, just as a hard disk, a floppy disk, etc. existing at present.
In the case when data on an existing recording medium is treated in a file format, a file management system (hereinafter referred to as a file system) peculiar to each recording medium is required, just as FAT (File Allocation Table) for a hard disk and a floppy disk, or CDFS for a CD-ROM. However, no file system is available for-the DV at present.
It is herein thought to adopt an existing file system, such as the FAT or CDFS, for the DV. However, the FAT and CDFS are file systems for media capable of carrying out random access, such as magnetic disks and magneto-optic disks; if the above-mentioned existing file systems are adopted for a medium like a magnetic tape for the DV and the like wherein sequential access is carried out basically, a problem of requiring longer time for access or the like is caused.
5) Furthermore, the MPEG2-coding system is one of typical compression formats of video/audio information; in order to transmit this, the MPEG2-TS (Transport Stream) Standard is available, and there is a method wherein MPEG2-coded audio/video information is divided into packets referred to as transport packets having a fixed length and then transmitted.
In the MPEG2-TS Standard, jitter is strictly required to be within xc2x130 ppm with respect to the arrival timing of a packet; in order to receive and record transmitted data by a recording/reproducing apparatus, to retransmit data reproduced by the recording/reproducing apparatus, to receive the data by a decoder and then to output images, the restoration of the packet output timing at the time of reception becomes a problem.
When transmitting transport packets by using a digital interface stipulated as IEEE1394 as a transmission line, a four-byte transmission time stamp is generated for each transport packet by an apparatus on the transmission side by using a CTR (Cycle Time Register) wherein 24.576 MHz count value used as the clock of the IEEE1394 transmission line is retained. Since the transmission time stamp is used to stipulate the timing when output is carried out from the receiving means of an apparatus for receiving the MPEG-TS signal to the inside of the apparatus, it is generated by calculating offset values such as a delay due to the buffer of the transmission means of a signal source, a delay due to the transmission line, and a delay due to the buffer of the reception means of the reception apparatus. A source packet is formed by adding the transmission time stamp to each transport packet of 188 bytes, and the packets are divided/connected in accordance with transmission ranges in the IEEE1394 transmission line and transmitted by isochronous communication wherein the real-time characteristic can be maintained.
The recording/reproducing apparatus generates timing information referred to as a recording time stamp on the basis of 27 MHz, i.e., the operation clock of the recording/reproducing apparatus so that the transmission time interval between packets at the time of recording can be maintained at the time of reproduction; and the information is added to the transport packets and recorded.
If a difference occurs between the operation clock of the recording/reproducing apparatus and the operation clock of a transmission destination, the difference accumulates during long-time recording, and data overflow or underflow occurs, whereby recording cannot be carried out properly; therefore, the operation clock of the recording/reproducing apparatus is required to follow the operation clock of the transmission destination. For this purpose, the content of each transport packet is analyzed, and the operation clock of the recording/reproducing apparatus is generated from the PCR (Program Clock Reference) value included therein by using a PLL (Phase Locked Loop) circuit.
At the time of reproduction, the recording/reproducing apparatus restructures transport packets, restores the same time interval between packets as that at the time of recording on the basis of the recording time stamp added to each restructured transport packet and the count value of the operation clock of the recording/reproducing apparatus, regenerates and adds the transmission time stamp, and carries out output and transmission to the IEEE1394 transmission line.
The packets transmitted from the recording/reproducing apparatus are received by the MPEG decoder, and transport packets are restructured. If a difference occurs between the operation clock of the recording/reproducing apparatus and the operation clock of the MPEG decoder at this time just as at the time of recording, data overflow or under flow occurs during long-time reproduction, whereby reproduction cannot be carried out properly; therefore, the operation clock of the decoder is required to follow the operation clock of the recording/reproducing apparatus. For this purpose, the content of each transport packet is analyzed, and the operation clock of the MPEG decoder is generated from the PCR (Program Clock Reference) value included therein by using a PLL (Phase Locked Loop) circuit.
As described above, in the conventional recording/reproducing apparatus, the restoration of the output timing by the detection of the transmission time stamp, and the restoration of 27 MHz clock by the analysis of a transport packet header and PCR, the generation and addition of the recording time stamp are required, and the apparatus has a disadvantage of becoming larger in size to carry out transmission, recording and reproduction. In particular, the analysis of the MPEG header requires simplified decoding, and the apparatus becomes larger in size. In the recording/reproducing apparatus which is supposed not to have any MPEG decoding means therein so that decoding is carried out by an external decoder, this impairs the essential purpose of reducing the size of the apparatus by not having any decoding means.
6) Furthermore, as PCs are improved in performance, data required to be treated in real time as video/audio data is increasingly treated by the PCs. The IEEE1394 is available as an interface for this purpose. Video/audio data can be transmitted in real time by using isochronous transmission wherein data is kept transmitted at nearly regular intervals, that is, one of the transmission modes of the IEEE1394.
Furthermore, the IEEE1394 is provided for the home-use digital VCR xe2x80x9cDVxe2x80x9d (Digital Video); by connecting it to a PC provided with the IEEE1394, data transmission can be carried out between the PC and the DV, and operation control for the DV can be carried out from the PC.
Furthermore, a hard disk has been used conventionally as a recording medium of a PC, and data transfer between two hard disks are carried out as described below.
A processor transmits a reading command to a SCSI I/F circuit; after receiving the reading command, the SCSI I/F circuit reads data having a predetermined size from one of the hard disks, and writes the data in a memory. Next, the processor transmits a writing command to the SCSI I/F circuit; after receiving the writing command, the SCSI I/F circuit takes out all data or only the required data written in the memory, and writes the data on the other hard disk. Furthermore, when data is transferred, the above-mentioned operation is repeated as necessary.
However, in the above-mentioned conventional configuration, when data is read from a hard disk, only the predetermined size of data can be read each time one reading command is issued from the processor; when reading more amount of data, a reading command is required to be issued newly. In the case when writing on a hard disk is carried out after reading from the hard disk is completed, and data reading from the hard disk is followed, it is necessary to wait for the completion of the writing. Therefore, a wait period is required when reading data from the hard disk.
Since data transfer is carried out in accordance with a data request from the SCSI I/F interface, the above-mentioned SCSI hard disk operates with no problem; however, in the case when a DV is used instead of one of the hard disks, and when the IEEE1394 Interface is used instead of the SCSI I/F, data packets having a predetermined size are transmitted/received nearly periodically; therefore, a problem of causing data loss is apt to occur during the wait period.
As described above, the various conventional technologies have the above-mentioned problems.
The present invention has the following objects, solving means and effects.
1) The present invention is intended to solve the above-mentioned problems, and it is also intended to provide a data recording/reproducing apparatus which, during transmission/reception between a control apparatus and the recording/reproducing apparatus, is capable of preventing the above-mentioned transmission/reception from malfunctioning by inputting an operation signal generated by an operation panel to a processor in the case when the control apparatus controls the recording/reproducing apparatus.
One aspect of the invention is a recording/reproducing apparatus comprising:
a transmission/reception means for transmitting/receiving data and command signals from a transmission line;
a recording/reproducing means for recording data received from said transmission/reception means on a recording medium during reception and for transmitting data reproduced from said recording medium to said transmission/reception means during transmission;
an operation means for generating an operation signal for determining the operation of said recording/reproducing means;
a control means for controlling said recording/reproducing means in accordance with said command signals or said operation signal; and
a switching signal generation means for outputting a switching signal for determining whether said operation signal is valid or invalid to said control means,
wherein said switching signal generation means outputs an operation means valid signal for validating said operation signal to said control means as said switching signal in the case when a command received from said transmission/reception means is a first command, and said switching signal generation means outputs an operation means invalid signal for invalidating said operation signal to said control means as said switching signal in the,case when a command received from said transmission/reception means is a second command, and
said control means validates said operation signal output from said operation means in the case of receiving said operation means valid signal, and said control means invalidates said operation signal output from said operation means in the case of receiving said operation means invalid signal.
Another aspect of the invention is a recording/reproducing apparatus comprising:
a transmission/reception means for transmitting/receiving data and command signals from a transmission line, and generating a transmission line reset signal in the case when the connection of said transmission line is disconnected;
a recording/reproducing means for recording data received from said transmission/reception means on a recording medium during reception and for transmitting data reproduced from said recording medium to said transmission/reception means during transmission;
an operation means for generating an operation signal for determining the operation of said recording/reproducing means;
a control means for controlling said recording/reproducing means in accordance with said command signals or said operation signal; and
a switching signal generation means for outputting a switching signal for determining whether said operation signal is valid or invalid to said control means,
wherein said switching signal generation means outputs an operation means valid signal for validating said operation signal to said control means as said switching signal in the case of receiving said transmission line reset signal from said transmission/reception means, and
said control means validates said operation signal output from said operation means in the case of receiving said operation means valid signal.
Still another aspect of the present invention is a recording/reproducing apparatus comprising:
a transmission/reception means for transmitting/receiving data and command signals, and for receiving manufacturer information from a transmission line;
a recording/reproducing means for recording data received from said transmission/reception means on a recording medium during reception and for transmitting data reproduced from said recording medium to said transmission reception means during transmission;
an operation means for generating an operation signal for determining the operation of said recording/reproducing means;
a control means for controlling said recording/reproducing means in accordance with said command signals or said operation signal;
a switching signal generation means for outputting a switching signal for determining whether said operation signal is valid or invalid to said control means; and
a memory for comparing said manufacturer information with specific manufacturer information stored in itself, and outputs a specific manufacturer information reception signal in the case of coincidence;
wherein said switching signal generation means outputs an operation means invalid signal for invalidating said operation signal to said control means as said switching signal in the case of receiving said specific manufacturer information reception signal from said memory, and
said control means invalidates said operation signal output from said operation means in the case of receiving said operation means invalid signal.
Yet another aspect of the present invention is a recording/reproducing apparatus comprising:
a transmission/reception means for transmitting/receiving data and command signals from a transmission line;
a recording/reproducing means for recording data received from said transmission/reception means on a recording medium during reception and for transmitting data reproduced from said recording medium to said transmission/reception means during transmission;
an operation means for generating an operation signal for determining the operation of said recording/reproducing means;
a control means for controlling said recording/reproducing means in accordance with said command signals or said operation signal;
a switching signal generation means for outputting a switching signal for determining whether said operation signal is valid or invalid to said control means; and
a binary switch for outputting a binary signal, wherein said switching signal generation means generates said operation means invalid signal only when said binary signal is a predetermined value, and
said control means invalidates said operation signal output from said operation means in the case of receiving said operation means invalid signal.
In accordance with the present invention, even if the operation signal generated by the operation panel is transmitted to the processor during the transmission/reception of data and commands between the control apparatus and the recording/reproducing apparatus, the processor controls the recording/reproducing unit on the basis of the switching signal generated by the switching signal generation unit, whereby the recording/reproducing apparatus can be prevented from malfunctioning.
2) Furthermore, in view of the above-mentioned problems of the conventional data recording apparatus, the present invention is intended to provide a data recording/reproducing apparatus, a file generation method and a file management method capable of generating file system information and controlling the generated files so that contents recorded on a recording medium can be confirmed more easily than ever before
Still yet another aspect of the present invention is a file system information generation method comprising:
a step of reproducing a recording medium on which record information regarding the division of recording target data and/or regarding the recording date and time of said data added to said recording target data is recorded;
a step of extracting said record information from data recorded on said recording medium;
a step of judging the division positions of said recording target data from said extracted record information on the basis of a predetermined reference; and
a step of generating file system information including data divided at said division positions.
A further aspect of the present invention is a data recording apparatus comprising:
a recording means for recording, on a predetermined recording medium, record information regarding the division of said recording target data and/or regarding the recording date and time of said data added to said recording target data;
a reproducing means for reproducing said recording medium;
an extraction means for extracting said record information from said recording target data recorded on said recording medium; and
a filing means for judging the division positions of data recorded on said recording medium on the basis of a predetermined reference from said record information extracted from said extraction means.
A still further aspect of the present invention is a file management method comprising:
a step of recording subsequent data after data having already been recorded on a recording medium on the basis of predetermined recording start position information;
a step of recording and controlling information indicating the recording end position of said subsequent data as said recording start position information for starting the recording of subsequent data;
a step of generating file system information regarding all of said recorded data; and
a step of recording said generated file system information after said subsequent data.
A yet further aspect of the present invention is a file management method comprising:
a step of recording subsequent data after data having already been recorded on a recording medium on the basis of predetermined recording start position information;
a step of generating file system information regarding all of said recorded data;
a step of repeatedly recording said generated file system information in a plurality of areas after the recording end position of said subsequent data; and
a step of recording and controlling information indicating predetermined positions among said plural areas as said recording start position information for starting the recording of said subsequent data.
A still yet further aspect of the present invention is a file management method comprising:
a step of recording subsequent data after data having already been recorded on a recording medium on the basis of predetermined recording start position information in a recording apparatus for recording data in one or more divided areas and for recording information regarding positions wherein said areas are recorded;
a step of generating file system information regarding all of said recorded data;
a step of recording said generated file system information as areas different from said subsequent data after said subsequent data; and
a step of recording and controlling information indicating the recording end position of said file system information as said recording start position information for starting the recording of subsequent data.
One aspect of the present invention is a data recording apparatus for starting recording data from the practical head of a recording medium and for recording recording end position information indicating the end position of said recording, comprising:
a file system information generation means for generating file system information regarding said data;
a first recording means for recording said data and said file system information; and
a second recording means for recording said recording end position information.
In accordance with the present invention, it has an advantage wherein contents recorded on a recording medium can be confirmed more easily than ever before. By recording file system information, data to be recorded can be filed and controlled; when reproduction is attempted after this cassette is ejected once, the contents recorded on the recording medium can be confirmed easily. Furthermore, processes such as dubbing, editing, deletion, division and the like of recorded data can also be carried out easily by indicating a file as a unit. Moreover, when data on the display screen is used as file system information, the content of the data can be confirmed by video, and therefore, can be confirmed easily. In addition, compatibility with a conventional data recording apparatus can be attained. The above-mentioned effects are provided, and their practical effects are significant.
3) Furthermore, in view of the above-mentioned conventional problems, the present invention is intended to provide a data recording/reproducing apparatus and a file management method capable of carrying out file management capable of treating data having a real-time characteristic.
Another aspect of the present invention relates to a file management method for a system for recording, on a recording medium, the medium information of the above-mentioned recording medium itself, one or more files and file system information for each of the above-mentioned files, wherein the above-mentioned file system information has real-time characteristic identification information for indicating whether data in files has a real-time characteristic or not.
Still another aspect of the present invention is a file management method for a system for recording, on a recording medium, the medium information of said recording medium itself, one or more files and file system information for each of said files, wherein rate information indicating the original data rate of data is used for files including data having a real-time characteristic as said file system information.
Yet another aspect of the present invention is a file management method for a system for recording, on a recording medium, the medium information of said recording medium itself, one or more files and file system information for each of said files, wherein in the case when the original data rate of data is variable, the maximum rate information indicating the maximum data rate among said rates is used for files including data having a real-time characteristic as said file system information.
A Further another aspect of the present invention is a file management method for a system for recording, on a recording medium, the medium information of said recording medium itself, one or more files and file system information for each of said files, wherein file size information indicating a time required for the original data rate of data is used for files including data having a real-time characteristic as said file system information.
A further aspect of the invention is a data control apparatus comprising a transfer means for transmitting control instructions to a data recording/reproducing apparatus for recording/reproducing one or more pieces of digital data, and for transmitting/receiving data, wherein said transfer means transmits/receives data for files including data having a real-time characteristic at a transfer rate set on the basis of information regarding data rates used as file file system information.
In accordance with the present invention, by recording file system information, data having a real-time characteristic, such as video and audio data, can be treated. Furthermore, even data having a variable transfer rate can be treated in consideration of the difference between the transfer rate and recording rate. The practical effect of the present invention is significant in a present situation wherein various video and audio data as well as simple numeral data and text data are increasingly being used as data to be treated as files.
4) Furthermore, in view of the above-mentioned conventional problems, the present invention is intended to provide a file system information generation apparatus and a file system information analysis apparatus for generating file system information constituting a DV file system required to record and control computer data in a file format on a DV and for recording the information at a predetermined position on a tape.
A still further aspect of the present invention is a file system information generation apparatus for generating file system information for controlling data recorded on a recording medium,
wherein the minimum structural unit of said data is a file, and the maximum structural unit of said data is a volume,
said volume is a first hierarchical level, a second hierarchical level is a root directory, and plural hierarchical levels from a third hierarchical level to the Mth (Mxe2x89xa73) hierarchical level are files or directories, thereby providing plural hierarchical levels,
said file system information is formed of information comprising entries used as units,
each of said entries has an entry ID for identification of each,
an entry is generated from information for controlling said volume,
an entry is generated for each of said directories from information for controlling said directories,
an entry is generated for each of said files from information for controlling said files,
said volume entry has information regarding said entry ID of said root directory,
each of said entries generated for directories has information regarding the entry ID of said entry generated for a directory belonging to said directory or the entry ID of said entry generated for a file belonging to said directory as a content entry ID,
each of said entries generated for files and each of said entries generated for directories have information regarding the entry ID of said entry generated for a file or a directory belonging to a directory to which said file or said directory belong as a next entry ID, and
all files or directories under said volume are designated once by said next entry IDs and said content entry IDs.
A yet further aspect of the invention is a file system information analysis apparatus for analyzing file system information for controlling data recorded on a recording medium,
wherein said entries generated for said volume, directories and files are analyzed from file system information generated such that:
the minimum structural unit of said data is a file,
the maximum structural unit of said data is a volume, said volume is a first hierarchical level, a second hierarchical level is a root directory, and plural hierarchical levels from a third hierarchical level to the Mth (Mxe2x89xa73) hierarchical level are files or directories, thereby providing plural hierarchical levels,
said file system information is formed of information comprising entries used as units,
each of said entries has an entry ID for identification of each,
an entry is generated from information for controlling said volume,
an entry is generated for each of said directories from information for controlling said directories,
an entry is generated for each of said files from information for controlling said files,
said volume entry has information regarding said entry ID of said root directory,
each of said entries generated for directories has information regarding the entry ID of said entry generated for a directory belonging to said directory or the entry ID of said entry generated for a file belonging to said directory as a content entry ID,
each of said entries generated for files and each of said entries generated for directories have information regarding the entry ID of said entry generated for a file or a directory belonging to a directory to which said file or said directory belong as a next entry ID, and
all files or directories under said volume are designated once by said next entry IDs and said content entry IDs.
In accordance with the present invention, just as conventional magnetic disc media such as hard disks, floppy disks and CD-ROMs, even magnetic tape media for a DV and the like can treat file format data. In addition, it is possible to generate file system information for controlling file format data and to analyze the generated file system information.
5) Furthermore, the present invention is intended to solve the above-mentioned problems, thereby being capable of restoring packet output timing during reproduction by using minimal additional circuits in the case of recording MPEG2data, and being capable of recording data in the MPEG2transport stream format while the existing digital VCR xe2x80x9cDVxe2x80x9d (Digital Video) format is utilized in particular.
A still yet further aspect of the present invention is a recording/reproducing apparatus for receiving and recording digital data transmitted via a transmission line, and for reproducing and transmitting said recorded digital data to said transmission line,
wherein when each packet constituting said digital data is transmitted through said transmission line, said each packet is generated on the basis of output timing from a signal source to a transmission means connected to said transmission line, and a transmission time stamp used as information added to all or part of said packets is recorded while being kept added to each of said packets.
One aspect of the present invention is a recording/reproducing apparatus for receiving and recording digital data transmitted via a transmission line, and for reproducing and transmitting said recorded digital data to said transmission line,
wherein the type of said digital data is discriminated, depending on said type, switching is carried out between recording with said transmission time stamp kept added to said each packet constituting said digital data and recording without said time stamp, and information indicating whether said time stamp has been added or not is also recorded.
21-th present invention (corresponding to claim 58) is a recording/reproducing apparatus for receiving and recording digital data transmitted via a transmission line, and for reproducing and transmitting said recorded digital data to said transmission line,
wherein the type of said digital data is discriminated, depending on said type, switching is carried out between recording with said transmission time stamp kept added to said each packet constituting said digital data and recording without said time stamp, and information indicating whether said time stamp has been added or not is also recorded.
In accordance with the present invention, packet output timing during reproduction can be restored by using minimal additional circuits in the case of recording MPEG2data. Furthermore, data in the MPEG2transport stream format can be recorded while compatibility with the existing digital VCR format is maintained in particular.
6) Furthermore, in view of these conventional problems, the present invention is intended to provide a method of writing stream data being kept output at nearly regular intervals at all times on a recording medium without data loss in a PC, and a method of reading data from the recording medium and transmitting the data as stream data being kept transmitted at nearly regular intervals at all times in the PC.
A another aspect of the present invention is a method of writing stream data on a recording medium in a system comprising:
a stream data output unit for continuously outputting data at all times at substantially regular intervals;
a first interface for receiving said stream data;
a recording medium;
a second interface for writing data on said recording medium;
a memory for temporarily storing data;
a processor for controlling the operation of said first interface and said second interface; and
a bus for connecting said first interface, said second interface, said memory and said processor,
wherein said processor transmits a reception command to said first interface and a writing command to said second interface, respectively,
after receiving said reception command, said first interface sequentially writes said received stream data in said memory through said bus, and
after receiving said writing command, said second interface sequentially reads a necessary portion from said stream data written in said memory through said bus, and writes said portion in said recording medium.
Still another aspect of the present invention is a method of writing stream data on a recording medium in a system comprising:
a stream data output unit for continuously outputting data at all times at nearly regular intervals after receiving an output start command;
a first interface for receiving said stream data and transmitting a control command to said stream data output unit;
a recording medium;
a second interface for writing data on said recording medium;
a memory for temporarily storing data;
a processor for controlling the operation of said first interface and said second interface, for generating the control command of said stream data output unit, and for outputting to said first interface; and
a bus for connecting said first interface, said second interface, said memory and said processor, wherein said processor transmits a reception command to said first interface and a writing command to said second interface, respectively, after transmitting said output start command as said control command to said stream data output unit through said first interface,
after receiving said reception command, said first interface sequentially writes said received stream data in said memory through said bus,
after receiving said writing command, said second interface sequentially reads a necessary portion from said stream data written in said memory through said bus, and writes the portion in said recording medium,
in the case when necessary data cannot be written completely at the time of writing on said recording medium, said processor transmits a data retransmission command as said control command to said stream data output unit through said first interface,
said first interface sequentially writes said received steam data in said memory through said bus, and
said second interface reads a portion not written at the last time from said stream data written in said memory through said bus, and writes said portion on said recording medium.
Yet another aspect of the present invention is a method of reading stream data from a recording medium in a system comprising:
a stream data input unit for continuously outputting data at all times at substantially regular intervals;
a first interface for transmitting said stream data;
a recording medium;
a second interface for reading data from said recording medium;
a memory for temporarily storing data;
a processor for controlling the operation of said first interface and said second interface; and
a bus for connecting said first interface, said second interface, said memory and said processor,
wherein said processor transmits a transmission command to said first interface and a reading command to said second interface, respectively,
after receiving said reading command, said second interface reads data from said recording medium, and writes through said bus, and
after receiving said transmission command, said first interface reads data written in said memory through said bus, and transmits as said stream data to said stream data input unit.
In accordance with the present invention, once the processor issues the reception command and the writing command, the process of the IEEE1394 Interface and the process of the SCSI Interface are conducted in parallel, whereby all of the received data or required data among the received data can be written completely on the hard disk.
In addition, once the processor issues the reception command and the writing command, the process of the IEEE1394 Interface and the process of the SCSI Interface are conducted in parallel; furthermore, in the case when a data loss occurs, the processor transmits the retransmission command to the DV, whereby the same data is received a plurality of times to recover the lost data, and the required data can thus be written in the hard disk completely.
Moreover, once the processor issues the transmission command and the reading command, the process of the IEEE1394 Interface and the process of the SCSI Interface are conducted in parallel, whereby data read from the hard disk can be transmitted to the DV via the IEEE1394 Interface without interruption.